The present invention relates to a surround sound outputting device and a surround sound outputting method.
In the surround sound system, commonly a plurality of speakers are arranged around a listener, and sounds are provided to the listener with a sense of realism when the sounds on respective channels are output from respective speakers. In such case, since a plurality of speakers are arranged in the interior of a room, such problems arise that a space is needed, signal lines become a hindrance in the room, or the like.
As the technology to solve such problems, the speaker array devices mentioned hereunder have been proposed. That is, the sounds on respective channels are output from the speaker array device to have the directivity (as a beam) respectively, and are caused to reflect from left/right and rear wall surfaces of the listener, and the like. The sounds on respective channels arrive at the listener from reflected positions. As a result, the listener feels as if the speakers (sound sources) for outputting the sounds on respective channels are located in the reflecting positions. According to this speaker array device, the surround sound field can be produced not by providing a plurality of speakers but by providing a plurality of sound sources (virtual sound sources) in the space.
In Patent Literature 1, the technology to set the parameters concerning the shaping of the sounds on respective channels into the beam based on the user's input is disclosed. In the sound reproducing device disclosed in Patent Literature 1, emitting angles and path distances of the sound beams on respective channels are optimized based on the parameters (dimensions of the room in which the sound reproducing device is provided, a set-up position of the sound reproducing device, a listening position of the listener, etc.) input by the user.
Also, in Patent Literature 2, the technology to make fully automatically the above settings is disclosed. The sound beam is output from the main body of the speaker array device set forth in Patent Literature 2 while shifting an emitting angle respectively, and the sound beams are picked up by the microphone that is provided in the listener's position. Then, the emitting angles of the sound beams on respective channels are optimized based on the analyzed result of the sounds picked up at the emitting angles respectively.    [Patent Literature 1] JP-A-2006-60610    [Patent Literature 2] JP-A-2006-13711
In the technology disclosed in Patent Literature 1, such a problem existed that the optimization of parameters cannot be attained depending on the shape and the installing location of the room in which the voice reproducing device is installed. That is, various parameters must be input based on the premise that the listener listens the sound on the front side of the sound reproducing device installed in the room having a rectangular parallelepiped shape, and the like. In a situation that the room has an irregular shape, there is an impediment to user's listening, or the listener listens the sound in a position that gets out of the front of the sound reproducing device, or the like, the emitting angles of the sound beams on respective channels cannot be adequately calculated. Also, such a problem existed that the parameter setting becomes troublesome because the user must measure/input manually the dimensions of the room, positions of the voice reproducing device and the listener, and the like.
In the technology disclosed in Patent Literature 2, a sound pressure of the picked-up sounds is analyzed every emitting angle of the sound beam. In this case, it is not considered at all via what paths the sounds being output at respective emitting angles arrive at the microphone respectively. As a result, it is possible that the paths of the sound beams are estimated incorrectly and the emitting angles of the sounds on respective channels are set incorrectly.